Machine press



Sept- 6, 1966 SHOZO SHIOKAWA 3,270,665

MACHINE PRESS Filed July 10, 1964 4 Sheets-Sheet 1 A ii Z D INVENTOR BYLama W Sept. 6, 1966 SHOZO SHIOKAWA 3,270,665

MACHINE PRESS Filed July 10, 1964 4 Sheets-Sheet 2 INVENTOR P 1966 SHOZOSHIOKAWA 3,270,665

MACHINE PRESS Filed July 10, 1964 4 Sheets-Sheet 5 INVENTOR.

BY W W M #M/ Sept. 6, 1966 SHQZO s o w 3,270,665

MACHINE PRESS Filed July 10, 1964 4 Sheets-Sheet 4.

INVENTOR.

BY ZJ M W United States Patent 3,270,665 MACHINE PRESS Shozo Shiokawa,28 Sone-Nishimaclri, 2-chome, Toyonaka, Osaka-fu, Japan Filed July 10,1964, Ser. No. 381,663 Claims priority, application Japan, July 15,1963, 38/ 38,439 1 Claim. (Cl. 100-282) The present invention relates toan improvement in a machine press.

' A particular object of the invention is to provide a machine pressthat can apply a large force effectively, although very simplyconstructed. A further object of the invention is to provide a press inwhich the pressing power of the ram increases in comparison with therevolving power of the crank, whereby it is possible to obtain a largepressing power with a small motive power and to provide a compact buthighly eflicient press.

Machine presses which have hitherto been used in general are designedin. such a way that a vertical ram is connected with a crank shaft towhich motive power is conveyed from a flywheel, and thereby convertingthe rotation of the crank to a vertical movement and conveying themovement direct to the vertical ram.

On account of such a structure as described above, the pressing power ofthe vertical ram is almost same as the resolving power of the crank andaccordingly, in order to increase the pressing power, it becomesnecessary to increase the motive power supplied to the crank.

In case of the so-called power press which needs large motive power, thesize of the press as a whole must therefore become large. Thus, it hasdisadvantages such as being not only uneconomical in every respect butalso diflicult to operate and yet high in price.

To overcome such disadvantages of the conventional press asabove-mentioned, the inventor has designed a compact but highlyefficient press which produces a large pressing power with a smallmotive power by means of, as explained in the following, setting alever-plate connected to a crank mechanism so that it swings with themain shaft as a fulcrum, the lever-plate and a ram-linking plate beingpivoted on the same main shaft, and the two plates being coupled to eachother by a linking mechanism when the ram comes down, thus increasingthe pressing power of the ram in comparison with the revolving power ofthe crank.

The invention will now be described in connection with the accompanyingdrawings in which:

FIG. 1 is a front view of an embodiment of the present invention; FIG. 2is a vertical sectional view of the embodiment of FIG. 1; FIG. 3 is ahorizontal section along the line AA in FIG. 2; FIG. 4 is a side view ofthe second embodiment of the present invention partially in section;FIG. 5 is a horizontal section thereof; and FIG. 6 is a side view of athird embodiment partially in section.

In the drawings, the upper end of a lever 1 is pivoted on a main shaft 3which is positioned at the upper front in the frame 2 of the press, andthe lower end of lever 1 has a long slit 6 therein in which a slidingpiece 5 of a crank shaft 4 slips.

By a crank mechanism, the lever 1 swings with the said main shaft 3 as afulcrum. On the main shaft 3 is pivoted the back center of a two partram-linking plate 7 in such a way as to hold the lever 1 on both sidesthereof, the parts of the ram-linking plate being joined by a connectingpart 7'. The top of the ram-linking plate 7 is also pivoted on a pin 8on an adjusting screw cylinder 10' which is threaded onto an adjustingscrew shaft 10 of the ram 9. Further, the upper end of the ram-linkingplate 7 is always pulled backward by a spring 11, whereby it tends topush the ram 9 upward.

The lever 1 and the ram-linking plate 7 are linked with each other by apawl means 12. This mechanism consists of a pawl 13 pivotally mounted ona pin 14 on the upper part of the ram-linking plate 7, the pawl 13 beingpositioned so that the free end thereof can fall into a notch 15 on theupper side of the lever 1 when a detent 17 pivotally mounted on frame 2is swung out from in front of projection 13 on the pawl 13 by pressingdown on a pedal 16 linked by link 18 to the other end of detent 17, thusreleasing the pawl 13. The weight of pawl 13 causes its free end to fallinto the notch 15.

Character 19 indicates a motor; '20 is a belt pulley; 21 is a piniongear; 22 is a gearwheel to turn the crank 4 around; and 23 is a flywheel(FIG. 1).

The press works as follows. When the motor 19 runs and the belt pulley20 rotates, the gearwheel 22 engaged with a group of pinion gears 21turns and so does the crank 4. Thereby, the sliding piece 5 slidesinside the long slit 6 in the lever 1, and makes the lever 1 swing upand down with the main shaft 3 as a fulcrum.

When the pedal 16 is not stepped on, the movement of the lever 1 is notconveyed to the ram-linking plate 7, because the hook 17 catches on aprojecting part 13 of the pawl 13, preventing the latter from droppinginto the notch 15 of the lever 1. On the other hand, when the pedal 16is stepped on and goes down with an axis 16', at the other end as afulcrum, the link 18 is pulled down, releasing the hook 17 from itscontact with the projecting part 13 of the pawl 13. Then, the pawl 13,under the effect of gravity drops into notch 15 of the lever 1.

Accordingly, when the lever 7 revolves with the main shaft 3 as itscenter, and its end pushes the ram 9 downward through the adjustingscrew cylinder 10' and the adjusting screw lever 10. On this occasion,the ram 9 is, as stated above, given a pressing power by the lever 1through the ram-linking plate 7 which is far shorter than thelever-plate 1 and consequently, the pressing power increases remarkably.

When the lever 1 moves downward the next time in accordance with therotation of the crank 4, the projecting part 1' of the lever 1 pressesthe connecting part 7 of the ram-linking plate 7. Thereby, theram-linking plate is turned in the opposite direction (clockwise) withthe main shaft 3 as a fulcrum, pulling the vertical ram 9 up.

FIGS. 4 and 5 illustrate the second embodiment of the present invention.In this case, the motor 19, the belt pulley 20 and the flywheel (notshown) are set inside the frame 2 of the press. All the referencenumerals in these drawings designate the same parts as in FIGS. 1 and 2.Further, it should be noticed in the second embodiment that the lever 1has a long slit 1" in which the shaft of the gear 22 slides, and thatmaking use of a spa-cc inside the frame 2 of the press, the swinging endof the lever 1 extends to the bottom, where it is connected with thecrank mechanism 4. Thus, the pressing power of the ram 9 is increasedfurther as the result of the lever 1 being very long.

FIG. 6 illustrates the third embodiment of the present invention. Inthis case, the motor 19 and the belt pulley 20 are :set inside the frame2 of the press, having the crank mechanism 4 located between them.

As already explained, the present invention consists of pivoting on thesame main shaft both the lever which by the crank mechanism swings withthe main shaft as a fulcrum and the ram-linking plate which is connectedat its other end with the ram, and linking the lever with theram-linking plate by a pawl mechanism when the ram comes down.

Because of this structure, the present invention has advantages that thepressing power of the ram increases in comparison with the revolvingpower of the crank, whereby it is possible to obtain a large pressingpower with a small motive power and to manufacture a compact but highlyefiicient press.

What I claim is:

A machine press comprising a vertically movable ram member, a ramlinking plate pivotally coupled to said vertically movable ram member, amain shaft mounted in a fixed position on said press and on which saidram linking plate is pivotally mounted and from which said ram plateextends in one direction toward said pivotal coupling, a lever havingone end pivotally mounted on said main shaft and extending from saidmain shaft in substantially the opposite direction from the directionthe ram linking plate extends from said main shaft, drive means coupledto the other end of said lever for pivoting said lever around said mainshaft, said drive means including a gear wheel having its centerpositioned between the ends of said lever, said gearwheel having a shaftabout which said gearwheel rotates, said lever having a slot therein, acrank on said gearwheel shaft and sliding in said slot, said slotextending in the direction of the length of said lever and pawl meanscoupling said ram linking plate and said lever and engaging said leverat a point substantially on the opposite side of said main shaft fromthe coupling of said ram linking plate and said ram.

References Cited by the Examiner UNITED STATES PATENTS 2,339,456 1/1944Budlong 83630 x FOREIGN PATENTS 136,776 3/1950 Australia.

WALTER A. SCHEEL, Primary Examiner.

BILLY J. WILHITE, Examiner.

